Yu-Gi-Oh/Zerozerock, A Feint Plan
For zerozerock, if you only have face-up ATK mode monsters with 0 ATK on your field, is your opponent able to attack you directly?
For A Feint Plan, if you only have face down monsters on your field, is your opponent able to attack you directly?
No, your opponent cannot attack you directly if they cannot attack any of your monsters while Zerozerock is in effect. The same thing applies for A Feint Plan. Your opponent cannot directly attack you if all of your monsters are face down.
The only exception to this is if the opponent's monster specifically states that it will be able to target you directly because of an effect from the monster or an effect from another spell card. If this is the case, then they may be able to attack you directly due to their card's effect.